TWO YEARS AGO -- THE MAJOR WAY TO SAVE ENERGY AT home was to apply weatherstripping, insulation and caulk. Hard work, but Americans have done it with gusto. Lovins says the real revolution is still to come: If four of the following technologies come into widespread use, they will save enough energy to eliminate nuclear power plants more than twice over.

* High-efficiency fluorescent light bulbs. The Philips SL*18 and the Mitsubishi Marathon draw 15 to 18 watts, but produce as much light as 50- to 75-watt incandescent bulbs. They cost from $15 to $22, but last up to 12 times longer than incandescents. Lovins estimates such bulbs would save the output of 30 large power plants. A random check revealed the SL*18 is available in about 20 percent of Washington-area lighting stores.

* New fluorescent tube units. Upgrades can squeeze quintuple efficiency from fluorescent tubes, such as those used in offices, factories, schools and stores. Lovins says widespread use would render unnecessary about 60 large power plants. Information is available from the Rocky Mountain Institute, Drawer 248, Old Snowmass, Colo. 81654.

* Superefficient refrigerator/freezers. The unit in the Lovinses' kitchen uses only 10 percent of the power of the average home unit. Its $1,900 cost is high, but Lovins says mass production would drop that. In general use, they would obviate 35 power plants. They are made by Sun Frost, Box DD, Arcata, Calif. 95521.

* Microchip controllers for electric motors. New technologies allow motors to draw less power when the load drops, doubling their overall efficiency. Lovins estimates these would save the output of 70 large power plants. RMI is preparing a report on specifications and sources.